1. Field of the Invention
The present invention relates to an external medicinal preparation useful for the healing of damaged skins such as burns or scalds, decubitus and open wounds, and more particularly to a powder preparation for healing damaged skins, which contains a sugar and povidone-iodine (polyvinyl pyrrolidone-iodine complex) as active ingredients.
2. Description of the Background Art
Sugars such as honey and molasses have conventionally been used, as folk medicine, for the treatment of burns or scalds and open wounds. These sugars have also been known to have bacteriostatic action and granulation tissue proliferating effects. Besides, povidone-iodine is a drug employed extremely widely as a bactericide throughout the world.
It has recently been reported that excellent effects of healing damaged skins were achieved when granulated sugar was mixed with a povidone-iodine preparation such as a Betadine ointment, Betadine solution, or Isodine gel (product of Meiji Seika Kaisha, Ltd.), and the resultant mixtures were applied to various damaged skins [R. A. Knutson et al., "Southern Medical Journal", Vol. 74, No. 11, 1329-1335 (1981); and Kiyokazu Sone et al., "Byoin Yakugaku (Hospital Pharmacology)", Vol. 10, No. 5, 315-322 (1984)].
However, the above-described compositions have involved problems that when stored at room temperature, they separate into two layers or change into the state like starch syrup, and moreover their active ingredients decompose to reduce the drug efficacy of the conposition. Therefore, they must have been stored in a cool and dark place. The active ingredients have however undergone decomposition in several months even when stored in this manner. It has been essential to prepare the compositions just before their use.
Studies have thus been conducted for overcoming such a disadvantage. As a result, in recent years, there has been developed an ointment preparation containing sucrose and povidone-iodine as active ingredients and having good long-term stability. Such an ointment preparation has been rated high by patients and the pharmacy interest in hospitals. However, there has been a demand for development of a preparation easy to use for applying to a wound surface rich in exudate or a deep wound, or to a granulation tissue surface easy to bleed, a patient having an acute pain or the like.
In view of the foregoing circumstances, a clinical experiment making use of a powder preparation, in which 3% of povidone-iodine powder was incorporated into sucrose, has been carried out ["Nichiidai-shi (Journal of Nippon Medical College)", Vol. 57, No. 2, 94 (1990)]. However, this powder preparation has involved a disadvantage that it undergoes a caking phenomenon during its storage for a long period of time or by vibrations upon its transportation due to the nature inherent in the sucrose amounting to 97% of the powder preparation, and so it can be neither taken out of a container nor spread to apply.